#include int isalnum(int c) { return isalpha(c) || isdigit(c); } int isalpha(int c) { return islower(c) || isupper(c); } int isblank(int c) { return c == ' ' || c == '\t'; } int iscntrl(int c) { return c <= 0x1f || c == 0x7f; } int isdigit(int c) { return '0' <= c && c <= '9'; } int isgraph(int c) { return isalpha(c) || isdigit(c) || ispunct(c); } int islower(int c) { return 'a' <= c && c <= 'z'; } int isprint(int c) { return isgraph(c) || c == ' '; } int ispunct(int c) { return ('!' <= c && c <= '/') || (':' <= c && c <= '@') || ('[' <= c && c <= '`') || ('{' <= c && c <= '~'); } int isspace(int c) { return c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v'; } int isupper(int c) { return 'A' <= c && c <= 'Z'; } int isxdigit(int c) { return ('0' <= c && c <= '9') || ('A' <= c && c <= 'F') || ('a' <= c && c <= 'f'); } int tolower(int c) { if (isupper(c)) return c - 'A' + 'a'; return c; } int toupper(int c) { if (islower(c)) return c - 'a' + 'A'; return c; }